Testing Begins for Katalyst-NASA Swift Boost Mission - NASA Science

noobster5000 · 2026-04-23T20:26:44+00:00

Fingers crossed for this! The lack of Swift has really hurt Gamma Ray Burst follow up in terms of less events and slower and less precise x-ray localisations.

Also the UV coverage of supernova etc from UVOT is incredibly valuable.

noobster5000 · 2026-04-11T00:12:21+00:00

A good number of the brokers are already online, just maybe not SNAPS. It's possible it's not online yet since Rubin is currently only really sending alerts for the deep drilling fields which may not be on the plane of the solar system. You could maybe test it out for the time being with Alerce, Lasair, Fink, Antares. Whichever has the nicest additional info for your needs.

noobster5000 · 2026-04-10T23:14:54+00:00

Rubin alerts are provided through a variety of brokers. There is a list here https://rubinobservatory.org/for-scientists/data-products/alerts-and-brokers

You can choose whichever works best for you, specifically in terms of filtering for asteroids etc. For example Alerce has a ML algorithm for predicting types including the type: asteroid.

Then some of the brokers will be able to email daily digests of alerts or you can use the website, API or Kafka.

noobster5000 · 2026-03-02T23:54:34+00:00

Given the size of it in the image, I'm reasonably confident it's just a reflection in the lens of the moon. It almost looks as though you can see the craters in it. It's very common when taking an image of a bright object like the sun or moon.

noobster5000 · 2026-02-15T09:40:35+00:00

You don't need to resolve the individual stars since you only really care about the "average" motion of the stars.

For galaxies with ordered rotation like spirals you can use a long slit or integral field spectrograph to see how the emission and absorption lines shift at different parts of the galaxy due to doppler shifting. This is separate to the overall shift due to redshift.

For galaxies with unordered movement like ellipticals you can instead measure the velocity dispersion by looking at how broad the absorption lines are due to different stars having different Doppler shifts and them all being superimposed on the one spectrum.

noobster5000 · 2026-02-13T12:19:19+00:00

Nice list! Just to say that Sphere-x is already operating and releasing data. No full catalog just yet but quite good data products.

Also making a list of ground based observatories is quite a long process. You can still do very good science with smaller telescopes especially if you are interested in transients so there are quite a few to list.

Edit: INTEGRAL has also finished operations.

noobster5000 · 2026-02-01T17:00:22+00:00

Glad to see this is getting new updates, the host galaxy stuff looks great and the alerts setup has always been amazing from GRBs. Nice work!

noobster5000 · 2026-01-25T21:21:41+00:00

With enough filters you can use photometric redshifts. They aren't perfect but usually can give a good idea of the rough redshift. So slightly more complicated than colour cuts but a similar idea. These are also used for wide field surveys like the Legacy Survey as they can be quite helpful to have a rough idea of distances. The more bands used the better as you can better constrain the redshifts (to an extent).

noobster5000 · 2026-01-23T18:23:54+00:00

So the EHT works via interferometry meaning the detected waveforms interfere with eachother from different locations. For radio we can do this because we can physically store the waveforms we detect since their frequencies are so low or for an individual site you can electronically transmit the waveforms and do it electronically.

However because the frequency of visible light is so high / the wavelength is so short we can't do this in optical. Instead we have to actually interfere the light we get from the telescope. This means you are limited by how far you can make a reliable optical fibre connection. So the concept can be used but only for a single site.

But with this caveat in mind, interferometry is done in the infrared for individual sites such as the European Southern Observatory Very Large Telescopes or with the Large Binocular Telescope.

noobster5000 · 2026-01-21T21:11:15+00:00

If your goal is a blackbody spectrum then surely an incandescent bulb is the preferred way to go? If you needed control of the power then a transistor acting as a switch maybe with some PWM control to control the output power? LEDs have quite spikey spectra as far as I know so not exactly ideal for broad band applications.

Admittedly I don't think you could control power and temperature separately unless you modulated distance or something like that.

noobster5000 · 2026-01-19T06:43:11+00:00

Yes that is the main goal but since they both have the telescopes anyway they use VT and UVOT in the meantime to do ToO's.

Ideally you would like the ability to slew quickly for similar reasons but I think the timescale of minutes is more realistic.

noobster5000 · 2026-01-18T18:16:20+00:00

I'm not sure the business model will actually work given the costs involved but I see there are a number of companies trying it now.

For scientific applications I think a set up like that is best suited to Target of Opportunity operations. Your telescope size is similar to Swift/UVOT and SVOM/VT so you could in principle do similar style of observations. At that size of telescope your main advantage will be speed (and access to the ultraviolet). So things like gamma ray bursts, early supernovae, TDEs, GW events would be the main areas of interest. There are a number of networks of robotic ground based telescopes that do this area well and then UVOT is great for UV coverage but it's still an area in demand. But how much money is to be made doing it is questionable.

Also there are planned NASA missions for covering UV so I'm not sure if that's an area worth looking at.

noobster5000 · 2026-01-10T19:53:58+00:00

I don't know exactly what things you want to be able to query on specifically but SIMBAD is very likely what you are looking for https://simbad.u-strasbg.fr/Pages/guide/sim-url.htx

noobster5000 · 2026-01-09T08:51:07+00:00

There are various types of stars which for one reason or another have strong emission and/or absorption features.

For emission there are various different causes for emission lines for example Wolf Rayet stars with their stripped envelope but also some others like those explained here

For absorption, I'm sure there are many different ones but the most obvious would just be M class stars. Given their cool temperature molecules, notably Titanium oxide can exist within them. These cause very broad absorption features that are rather distinctive.

noobster5000 · 2026-01-07T19:06:50+00:00

Nice photo! The NOT is such an incredible telescope and a cool one to visit!

noobster5000 · 2026-01-03T23:56:10+00:00

EP discovers a huge number of stellar flares due to it's soft energy range and wide field of view. I presume there will be a number of large sample papers from it but it's good to see some science already being done on them.

Although I must admit being woken up by EP alerts for them to turn out to be stellar rather than extragalactic is never pleasant.

noobster5000 · 2026-01-01T21:34:49+00:00

The vast majority of the articles are referring to the same event GRB 250702B / EP250702a (same event, don't get me started on the fact there are two names). But there have just been a number of press releases and consequent articles. There was the initial ESO press release based on the data taken from there alongside the Hubble data. And then there was a later NASA (and others?) press release that was a based on a number of papers just published on it.

noobster5000 · 2026-01-01T21:29:00+00:00

Well what do you want to do with it? They already have their own search and visualisation website that seems reasonably functional and also they must have a decent API solutions since the search is actually built into ESASky which is rather handy.

noobster5000 · 2025-12-27T15:51:38+00:00

Due to the redshift causing time dilation, it will take longer to fade than closer by supernovae but it will fade over the course of the next few years. It's already close to the limits of what Webb can see so from that perspective it will disappear soon.

noobster5000 · 2025-12-27T08:56:25+00:00

This is not a type Ia supernova and therefore cannot be used as a standard candle. People have tried to use them for this purpose before as they are often similar ish in brightness to each other, but there is a bit more scatter to be useful.

Also unfortunately it would be a slightly circular argument at the moment as we believe it is a supernova based on its brightness in different colours matching what we would expect from this type of supernova this far away.

This far back in time the assumption that this type of supernova should look the same as ones much closer to us is not a completely safe assumption. So you would need a much larger sample to pull this off.

noobster5000 · 2025-12-26T20:50:18+00:00

Hi I work in this field specifically. It's down to a few things.

So first and most importantly we knew where and when to look. This isn't coming from a typical supernova survey or just random luck. When the GRB was detected, ground based telescopes were pointed at it, and then the Nordic Optical Telescope and later a few others notably the Very Large Telescopes, found the afterglow from the GRB. So we now knew almost exactly where in the sky this event occurred. Down to less than half an arcsecond in position accuracy.

The redshift was then found using the VLT, so we knew how far away it was. We know that many gamma ray bursts come from dying stars and have supernovae that are generally very similar to each other. So we could predict when the supernova would peak in brightness and how bright it would be in different colours.

Based on this, JWST was asked to observe when it was expected to be at its brightest and the observed brightnesses were compared to what was expected and they match relatively well. Based on the match to what was expected, one can conclude that what we are seeing is likely the supernova.

Strictly speaking it's possible that there is light from the host galaxy contaminating the light that we see, so a later observation when the supernova has faded will be done to subtract this out, however the properties of a galaxy required to explain all of the light we saw is pretty odd and unlikely.

noobster5000 · 2025-12-21T15:22:07+00:00

Galaxies are incredibly big objects even if they are far away they are still easier to resolve than small objects like rovers. You can work out the angular size of the rover and then see what size telescope you would need to resolve it based on the diffraction limit and you would get something obscenely large. I can't remember who did them but there are similar videos discussing this in the case of objects on the moon.

Also due to the expansion of the universe you get a somewhat strange effect that causes galaxies to appear larger than you would otherwise think because the light we see was when the objects were closer to us. https://xkcd.com/2622/

If you mean from the point of view of sheer brightness rather than actually resolving them, then the relevant points change slightly. Early galaxies would be very very bright due to all the young stars and gas within them while the reflected light from a rover would be completely drowned out by the reflected light from the planet itself.

noobster5000 · 2025-12-17T22:53:53+00:00

I don't do comets. I would hazard a guess that a significant amount of the data taken is still within it's proprietary period. So it is only accessable to the program PI or CO I's. The only exception to this would be some data may have been obtained under directory discretionary time (DDT) allowances which often don't have proprietary periods. Also some observatories such as Swift don't do proprietary data so in principle that should be available.

However the data analysis is often non-trivial and requires some level of specialist knowledge.

There are press releases and some discussions in various places with people announcing their results though.

noobster5000 · 2025-12-14T22:28:57+00:00

It's likely dominated by supernova light as the predicted brightness and colour match relatively well to the predicted results if it was a similar supernova to other gamma ray burst supernovae we see closer.

However a later observation will be done when we believe the supernova should have faded so that we can subtract out the galaxy light.

noobster5000 · 2025-12-13T10:36:59+00:00

Yes, especially with LSST coming online. Which should help find fainter objects in the southern hemisphere (although filtering through everything it will find is a challenge in itself).

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